Reducing Production of CO2 and CH4 from Peaty Paddy Soils through Applying Slag in South Sumatera, Indonesia

The change of anthropogenic peatlands to agricultural lands could have negative impacts, namely soil subsidence due to oxidation processes, and reduce the stock of soil organic carbon due to the increase of greenhouse gases (CO2 and CH4) emissions which contribute to global warming. Stability of converted peatlands could be increased through amelioration of soil by applying steel slag. A laboratory experiment was conducted with using factorial complete randomized design with ten combination treatments, including slag application, of peat soil samples collected from paddy fields in South Sumatera. This study determined the effect of steel slag application on reducing greenhouse gas (CO2 and CH4) production from cultivated peatland soils. The first factor of experimental treatment was peaty soil from 5 different locations, and the second factor was the application of steel slag. The highest production potentials of CH4 and CO2 were shown by peaty paddy soils from Kayu Agung and Plaju, respectively, while the lowest fluxes were shown by Indralaya’s peaty paddy soil. Peaty paddy soil from the Indrajaya site produced the lowest CO2 and CH4 compared with other sites. Application of steel slag ameliorant reduced CH4 and CO2 emissions by 19.24% and 18.95%, respectively, on average. Slag ameliorant also reduced acidity of peaty paddy soils.